Google Voice is a VoIP/SIP program that can be used to make free or very cheap phone calls to many countries around the world. If you’re located in the United States, then your calls to the USA or Canada will be completely free. Not only that, but the program comes with a rich feature-set that includes voicemail, conference calls and video conferencing, SMS to email, a voice transcription service and a full featured contact list that lets you manage all your contacts’ details.